Process of making sulfite liquor.



R. B.' WOLF.

PROCESS OF MAKING SULFITE LIQUOR.

APPLICATION FILED NOV. 17, 1909.

Patented May 26,

STATES PATENT OFFICE;

ROBERT B. WOLF, 'orBrinLIN, NEW nAMrsHmnhssIeNon, 'ro BURGESS or PORTLAND, MAINE, A CORPORATION or MAINE.

FIBRE 00.,

SULPHITE rnoonss or MAKING SULFITE motion.

Improvements in Processes of Making Sul- 'fite Liquor, of which the following is a i specification.

This strong This inventionrelates to the making of the acid for a sulfite process of paper pulp manufacture, and particularly to the production of an acid containing a bisulfite.

The particular apparatus discussed in this application is illustrative of my process as presented in a co-pending application, Serial No. 528,443.

production of high grade pulp of fi er and proper whiteness demands an acid containing a maximumamount of sulfurousacid and a certain predetermined, relatively smaller amount of basic bisulfite. Only enough of this base is needed to perform these functions, and anything in excess of this amount simply increases the sulfur and lime used.

My present invention relates to the completion of the reactions and changes producing the bisulfite in the acid in advance of the time that the acid is to' be raised to its maximum strength. This I secureby advancing certain of the chemical reactions I manufacture using cilitate and and by inducing others to take place in such times, orders and relations'as to make the final combination of the sulfur dioxid (S0,)

with water (H O) take place after all of the base has been converted to the bisulfite.

For the better illustration of the principles of myinvention which I will more fully set forth in the specification which follows, I will discuss as an illustrative example the formation of the acid element of sulfite pulp a calciumbase.

In my method, as I have stated, I advance certain of the reactions, particularly the formation of a basic sulfite, and introduce it in the acid system in such a manner as to fahasten the ultimate completion of the sulfites rior to the final reactions of the acid com ination.

- To make my invention describe its practice in clear I will now acid containing.ealcium'bisulfite for use 1n production of paper ess. In connection with this I have shown -1n the accompanying drawing a-systeni in the formation of an pulp by the sulfiteproc- Patented May 2t, 1914.

' which I have indicated the necessary apparatus.

-T-hrou-ghout specification and drawing like reference numerals are employed to in- 'dicate corresponding parts.

I first burn sulfur or sulfurous ores (S0 preferably under a slight vacuum or at most not more than atmospheric pressure.

I then cool the gas in the usual manner in coolers 3. I then treat the gas initially with lime water, preferably a fresh or unused lime water. This I find is advantageously accomplished by spraying the lime water into the gas during an agitation of, the gas and spray. F or example, I inject fresh lime water through nozzles 8 into a blower 4 in which agitators 6 are turning. The resultant li uid will contain a considerable amount 0 calcium monosulfite, with possibly some sulfate of lime formed by" S0, in the gas, and this I conduct to the lime tank for subsequent use aftermechanifoally separating the solution and gas. The

former falls in the 'bent ,foot' 10 of a tube 11 stirred by agitators 12 from which it spills through a pipe 16 to the tank 17 which is fed with lime. Fromthis initial treatment the sulfur gas (S0,) in excess is forced under the pressure of the blower 4: through the pipe 18- and successively into a series of tanks 21, 22 and 23, betweenwhich the lime .water containing calcium monosulfite passes in the oppositedirection through the pipes 30, 31 and 32. These tanks may be r of any number necessary. Ordinarily I have found three satisfactory. In the last tank 21 into which the liquid. enters '(the first throughwhich the gas passes) the bisulfite will be present without interfering with the combination of .the water and sulfurous acid gas, and the resultant acid will be strong and tions the amount of lime fed may be regulated to secure just the amount of bisulfite requirediin the liquor. place under pressure are more complete and rapid than they have heretofore been, and as an excess of sulfurous-acid gas is used the acid formed is much stronger.

In using the blower 4: there will be an excess of gas and a sulfurous acid gas discharge at the outlet 34 of the last tank 23. This excess I, therefore, treat as follows: I conduct through the pipe the gas to towers 35- and 38 filled with lime stone 36,

clear. By testing the solu- These actions taking-l through which a through pipes 39f-and 41'. The sulfurous b 3 fore, havean ionic reaction. In

-65 .ence of the carbonated water shower is falling acid gas, forming sulfurous acid,, forms monosulfite which is deposited on the stone, 5 and then being raised-to bisulfite is ultimately washed down and is carried" together with sulfurous acid in a solution which is pumped along by the pump 4t) through the succeeding tower to the lime tank 17 where they react on' the calcium hydrate forming calcium monosulfite.

,In conclusion it might be'w'ell to point out that the time required to convert' the monosulfite into thebisulfite is much greater than the timerequired' for the oonverslon of the hydrated lime into the monosulfite, which reaction takes place almost instantaneously', due to the fact that the, lime held indsuspension is partially soluble'in water an action of the S0 the lime 'in takes its place in the solution.

suspenslon We, therethe case of which is insoluble and also monosulfite,

there 1s no 1omc react10n,. for

crystalline,

the. action is upon the mass; also, this mass being crystalline, the speed with which the reaction takes place is necessar ly slow. This explanation is made to show how emential' it is to have the calcium hydrate mostly converted into the monosulfitebefore it enters the absorbing system.

The apparatus described and shown herein is claimed in my copending application No. 528,444, filed concurrently herewith.

It will be readily seen that various modi-' ..fications' in the materials and manner of handling may be made according to the system used or the results sought, all without departing from the spirit .of mv invention if within the limits of the appended claims. and desire to se-' What I, therefore, claim cure b Letters Patent is '1. 'l he process of makin sulfite liquor which consists in lpumping t e gas containing SO, into the a adding a small amount of a hquid carrying I a base partly in solution to the gas entering the pump, then allowin the gas to separate fromt-he treating liquid after passing the main body of basic hquid, an then treating the resulting basic hquid with said separated 'gas under counter current principle to produce the sulfite liquor.

2.- The process of makin which consists in pumping t ing SO, into the absorption apparatus in which the basic liqil'idandthe gas under pressure are systematically brought together onthe counter current principle to produce sulfite li uor, treating the resulting weak gases wit an absorbing liquid in the .presass and adding-the sulfite liquor liquid resultin from treating the resultant as soon as the ions are removed by the the gas under maximum sorption apparatus while I the pump, and then .addingsuch li uid to' pressure and 'on. the

e gas containthis'st'ep to the main ody of basic hquid. I

h process of making the acid of aprocessconsisting in forcing the gas containing $0 into the absorption apparatus while adding a small amount of a base part1 in solution to said gas, allowing. said igui to separate from the gas, addin said liquid to the main bodly of basic liqui then iquid with said separated-gas under pressure on the counter current principle, treating the resulting weak gases with an absorbing liquid inthe presence ofa carbonated base and adding the liquid resulting from thisstep to the main body 0 of basic liquid 4'. The process-of making the acid of a sulfite process consisting in forcing the gas c'ontaimng SO, into-the absorption a paratus while addmg a small, amount 0 milk as of lime to said as, allowing said liquid to separatefrom t e gas, adding said 11 uid to the main body of the basic liquid t en treatingthe resultant liquid with said separated gas under pressure onthe counter our rent principle, treatin the resultin weak gases with water in t e presence 0% limestone and adding the liquid resulting from this step to the main bod of basic liquid.

I 5. The process ofmal r ing the acid of a sulfite rocess consistinginemplo ingamain body 0' basic liquid having initial 'asic sulfite present therein, in treating said basic liquid with gas containing $0 under pressure, by the counter-current princi le of progres'j- 10o sion, in which progression t e formation of bisulfite issecured in ,an early part of the liquid current, anda maximum strength of ressure is maintamedatan earl part 0 the gas current, whereby the wea est gas meets liquid containing the greatest amount of uncombined' base and the strongest gas encounters liquid 7 containing substantially no uncombined base.

6. A process of making sulfite liquor which consists in maintaining a body of basic liquid, in forcing the gas contamlnlg $0 into an absorption apparatus in whic the basic'liquid and the as under pressure,

are systematically. ibr'ou t together on the 116 counter current pr1nc1p e to produce a suli -fite liquor under an excess of gas which es- 7 capes therefrom, treating said escapin excess gas toform a liquldcontaining' othcombmed and uncombmed sulfurous acid 120 and adding said combined and uncombine sulfurous acid to the main body of basic I liqyida .The process ofmaking sulfite process consisting 1n. inain body of basic liquid having initial basic sulfite present therein, in; treating the same with a gas containing SO under pressure by the counter current princi le of the acid of a employing a.

progression in which progression the ormai30- of the liquid current and gas of maximum strength under maximum pressure is maintained at an early part of the gas current, whereby the Weakest gas meets the liquor containing the greatest amount of uncombined base and the strongest gas encounters the liquid containing no combined base, but A with an excess of gas escaping from the treated liquid containing the greatest amount of uncombined base, and in treating said escaping gas to produce a liquid containing free sulfurous acid andsulfurous acid combined with a base, and in supplying said liquid thus formed to a mainbody 15- of basic liquid first described.

In testimony whereof, I have'aflixed my signature in presence of two Witnesses.

' ROBERT B. WOLF. Witnesses: Y

EDMUND SULLIVAN,

THOMAS W. ESTABROOK. 

